The discrete random variable X X\,X has the distribution X∼B(20,0.41)X \sim B(20, 0.41)X∼B(20,0.41).
Find P(3<X≤7)P(3 < X \le 7)P(3<X≤7).
A restaurant's records show that 30% of its customers order a starter. On one day a random sample of 50 customers is taken, and 9 of them order a starter. Stating your hypotheses clearly, test at the 5% significance level whether the proportion of customers ordering a starter has decreased.
32 exam-style questions on WJEC A Level Maths 2.5.1 Statistical hypothesis testing. Each one has a worked solution and a mark scheme showing where the marks go.